ATLAS sensitivity to Wtb anomalous couplings in top quark decays Aguilar Saavedra, Juan Antonio Carvalho, J. Castro, N. F. Onofre, Antonio Veloso, F. Top quark Atlas detector We study the sensitivity of the ATLAS experiment to Wtb anomalous couplings in top pair production with semileptonic decay, pp→tt̄→W+bW-b̄ with one of the W bosons decaying leptonically and the other hadronically. Several observables are examined, including the W helicity fractions and new quantities recently introduced, such as the ratios of helicity fractions and some angular asymmetries defined in the W rest frame. The dependence on anomalous couplings of all these observables has been previously obtained. In this work we show that some of the new observables also have smaller systematic uncertainties than the helicity fractions, with a similar or stronger dependence on anomalous couplings. Consequently, their measurement can significantly improve the limits on anomalous couplings. Moreover, the most sensitive measurements can be combined. In this case, the precision achieved in the determination of Wtb anomalous couplings can be of a few percent in the semileptonic channel alone. 2014-03-05T08:58:50Z 2014-03-05T08:58:50Z 2008 journal article Aguilar-Saavedra, J.A.; et al. ATLAS sensitivity to Wtb anomalous couplings in top quark decays. European Physical Journal C, 53(4): 689-699 (2008). [http://hdl.handle.net/10481/30672] 1434-6044 1434-6052 doi: 10.1140/epjc/s10052-007-0519-9 http://hdl.handle.net/10481/30672 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Società Italiana di Fisica